We examine the scattering of charged pions from the trinucleon system at a pion energy of 180 MeV. The motivation for this study is the structure seen in the experimental angular distribution of back-angle scattering for π + -3 He and π − -3 H but for neither π − -3 He nor π + -3 H. We consider the addition of a double spin flip term to an optical model treatment and find that, though the contribution of this term is non-negligible at large angles for π + -3 He and π − -3 H, it does not reproduce the structure seen in the experiment.